Implant screens are well known in the art of semiconductor fabrication. Implant screens are used to control the depth of an implant, and thus a resulting junction depth. The implant screen may also act as a protective etch stop in the formation of self-aligned contacts.
Typically, an implant screen comprises a thin oxide deposited over a semiconductor structure. The deposited screen oxide generally reduces space between components of the semiconductor structure. This reduction is problematic in high density circuits with tightly packed transistors and other components.